Division of Compensation Analysis and 

Support

Program Evaluation Report

Document Number: DCAS-PER-083 

Effective Date: 1/7/2019 

Weldon Spring Plant TBD Revision Page 1 of 3

Author: 

 Dave Allen, HP Team Leader

 Signature on file Date: 1/7/2019 Supersedes: none 

Approval

 J. W. Neton, Associate Director for Science

: Signature on file Date: 1/7/2019 

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE

DATE

DESCRIPTION

1/7/2019 1/7/2019 New document to determine the effect of 

revising ORAUT-TKBS-0028-4 and 

ORAUT-TBKS-0028-5 (Weldon Spring 

Plant TBD) on previously completed 

claims.

1.0 Description

A six section Technical Basis Document (TBD) for the Weldon Spring Plant (ORAUTTKBS-0028) is used for conducting dose reconstructions. Previous revisions to sections 

3 through 6 of this TBD were evaluated in DCAS-PER-051 which was issued on March 

4, 2015. Since that date, sections 4 and 5 were revised on 3/29/2017 and 3/14/2017, 

respectively. An additional revision to clarify language in both sections was issued on 

9/8/2017 and 8/31/2017, respectively. This PER considers the effect of these changes on 

dose reconstructions that were completed using previous versions of the TBD. 

2.0 Issue Evaluation 

In the March 2017 revisions, two changes were made to two parameters that affect both 

sections 4 (Occupational Environmental Dose) and section 5 (Occupational Internal 

Dose) of the Weldon Spring Plant TBD. These two parameters are the contribution of 

recycled uranium contaminants to internal dose and the specific activity of 1% enriched 

uranium. In both cases, the Weldon Spring Plant TBD references the Feed Material 

Production Center (FMPC) TBD (ORAUT-TKBS-0017). The values for the two 
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Program Evaluation Report

Document Number: DCAS-PER-083 

Effective Date: 1/7/2019 Page 2 of 3

parameters were revised in the FMPC TBD and, as a result, the Weldon Spring Plant 

TBD was revised.

The most recent revision to both sections of the TBD clarified that recycled uranium 

intakes are assumed to start in 1961. While it was clear in several places of the TBD, at

least one place in each TBD indicated recycled uranium exposures starting “after 1961”. 

That language was changed in the last revisions to make it clear that intakes are assumed 

to start in 1961. 

3.0 Plan for Resolving Corrective Action 

In considering the last revisions, all Weldon Spring Plant claims completed between 

March and September of 2017 were reviewed. Only one had employment in 1961. The 

dose reconstruction for that claim was reviewed and found that recycled uranium intakes 

were assigned in 1961. Therefore, no further consideration for this issue was necessary. 

To evaluate the remaining issues, a search was conducted for all claims with employment 

at any one of the three Weldon Spring facilities in the NIOSH claims tracking system 

(NOCTS). Additionally, a key word search was conducted on dose reconstruction reports 

for the word “Weldon”. These searches resulted in 330 unique claims being identified. 

From the list of 330 claims, 3 claims were identified as being completed with the current 

TBD and an additional 126 claims were identified as having probability of causation 

(POC) greater than 50%. Also, 51 claims had been pulled from dose reconstruction 

(primarily due to inclusion in the Mallinckrodt SEC) and 7 claims were active at NIOSH 

at the time of the search and would be completed using the current TBDs. Lastly, 2 

claims were determined not to have employment at Weldon Spring. They had been 

identified because the dose reconstruction report mentioned Weldon Spring but actually 

had no employment there and the Weldon Spring TBD was not used to estimate the dose. 

This left 141 claims to be evaluated. One of those claims met the criteria for the 

Mallinckrodt SEC and the dose reconstruction was done prior to the designation of that 

SEC class. Therefore, it was removed from evaluation under this PER. 

The remaining 140 claims were to be reevaluated under this PER, however, two of the 

claims were returned to NIOSH for a new dose reconstruction (for other reasons) before 

the evaluation occurred. A new dose reconstruction for these two claims would be 

completed using the current TBD, therefore those claims were removed from further 

consideration under this PER. Doses for the remaining 138 claims were recalculated 

using the current revisions of the TBD, as well as all other applicable procedures. The 

POC for 129 claims remained below 45%. Four claims resulted in a POC between 45% 

and 52%. For those claims IREP was run 30 times at 10,000 iterations per NIOSH 
Division of Compensation Analysis and 

Support

Program Evaluation Report

Document Number: DCAS-PER-083

Effective Date: 1/7/2019 Page 3 of 3

procedures. The resulting POC was less than 50% for all 4 claims. Five claims resulted 

in a POC greater than 50%.

NIOSH will provide the Department of Labor with the list of all the claims evaluated 

under this PER. Further, NIOSH will request DOL return the 5 claims that would now 

result in a POC greater than 50%.